A transfer case includes an input that transfers power from a vehicle engine to at least two different outputs. Typically, the transfer case includes one output for driving a rear drive axle and another output for diving a front drive axle. The transfer case also includes a declutch assembly that allows one of the first and second outputs, typically the output for the front drive axle, to be selectively disengaged from the input.
Transfer cases can have various configurations, including a two-speed configuration in which a user can select between a high range of operation and a low range of operation. For this type of transfer case, the declutch assembly includes independent shift mechanisms to engage the high and low ranges, and to engage and disengage one of the first and second outputs. This configuration requires a significant number of components, which accordingly increases cost and assembly time.
Further, this declutch assembly has a bolt-on attachment interface to the transfer case. Typically, the transfer case includes a two-piece housing. A declutch housing that encloses the declutch assembly is bolted onto an external portion of one housing piece, and includes an output yoke that is coupled to one of the front and rear drive axles. Another output yoke extends outwardly from the other housing piece opposite from the output yoke associated with the declutch assembly.
The distance between these two opposing output yokes is defined as “standout.” Conventional two-speed transfer cases have a long stand-out due to the bolt-on attachment interface of the declutch assembly. Long stand-outs are disadvantageous because the overall packaging envelope for the transfer case is increased, which decreases the amount of packaging space available for other driveline components.
Thus, there is a need for a more compact and cost-effective transfer case configuration.